Sample solution: Transfer Oral Suspension, equivalent to 160 mg of megestrol acetate, to a separatory funnel, add 50 mL of water and 40 mL of chloroform, and shake. Allow the phases to separate, and discard the aqueous layer.

Standard solution: 45 mg of USP Megestrol Acetate RS in a 250-mL volumetric flask. Add 12 mL of methanol, and place the flask in a warm water bath until the solid is dissolved. Dilute with Medium to volume. The final concentration is 180 µg/mL of megestrol acetate. Dilute with Medium, if necessary.

Sample solution: Transfer to the surface of the Medium in the dissolution vessel an accurately measured volume of Oral Suspension, freshly mixed and free from air bubbles, equivalent to 160 mg of megestrol acetate. At the sampling time, withdraw a volume of the solution under test and pass through a suitable filter with 0.45-µm pore size. Dilute with Medium, if necessary.

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of C24H32O4 released:

Result = (AU/AS) × (CS/V) × VD × (100/L)

AU

=

= absorbance of the Sample solution

AS

=

= absorbance of the Standard solution

CS

=

= concentration of the Standard solution (mg/mL)

V

=

= volume of Oral Suspension taken

VD

=

= volume of Medium, 900 mL

L

=

= label claim (mg/mL)

Tolerances: NLT 80% (Q) of the labeled amount of C24H32O4 is dissolved.

Test 2: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.

Medium: 0.5% sodium lauryl sulfate in water; 900 mL

Apparatus 2: 25 rpm

Time: 30 min

Detector: UV 292 nm, using 0.5-cm pathlength cuvettes

Standard solution: 45 mg of USP Megestrol Acetate RS in a 250-mL volumetric flask. Add 5 mL of methanol. Dilute with Medium to volume. Transfer 10 mL of this solution to a 100-mL volumetric flask, and dilute with Medium to volume. The final concentration is 18 µg/mL.

Sample solution: [NoteUse a separate syringe for each vessel. ] Withdraw more than 10 mL of the Oral Suspension, using a 10-mL syringe with a long cannula. Remove air bubbles from the syringe. Adjust the volume to the 10-mL mark on the syringe, and remove the needle. Wipe the tip of the syringe, and weigh (gross weight). Operate the apparatus, and rapidly dispense the Oral Suspension to the side of the vessel at about halfway from the bottom. Similarly dispense the Oral Suspension into other vessels. Weigh each syringe after dispensing the sample (tare weight). Record sample weights. After completion of the dissolution, pass an aliquot through a suitable nylon filter with 0.45 µm pore size, and dilute 2.0 mL of the filtrate with Medium to 50.0 mL to obtain a solution having a theoretical concentration of about 18 µg/mL.

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of C24H32O4 released:

Result = (AU/AS) × (CS/W) × VD × d × (100/L)

AU

=

= absorbance of the Sample solution

AS

=

= absorbance of the Standard solution

CS

=

= concentration of the Standard solution (mg/mL)

W

=

= weight of the Oral Suspension taken (mg)

VD

=

= volume of the Medium in the dissolution vessel, 900 mL

d

=

= density of the Oral Suspension (mg/mL), obtained by dividing the weight of Oral Suspension taken by 10 mL

L

=

= label claim (mg/mL)

Tolerances: NLT 80% (Q) of the labeled amount of C24H32O4 is dissolved.

Test 3: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.